feat: branch/PR naming standard CI check

Composite action that validates head branch and PR title against the
fritzlab naming standard (role/bug-id/kebab + [bug-id] titles).
Always exits 0 (warn-only) until the Bugs system is live.

- check.sh: validation logic (branch form, title form, bug-id cross-check)
- action.yaml: composite action wrapping check.sh
- tests/run: 20-case test matrix (valid/invalid/chore/mismatch/dfritz)
- .gitea/workflows/test.yaml: CI that runs the test suite

Closes fritzlab/agenthub#559

check.sh

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+# Branch and PR title naming-standard checker.
+# Always exits 0 — warn-only until the Bugs system is live and STRICT=1 is set.
+set -euo pipefail
+
+BRANCH="${HEAD_BRANCH:-}"
+TITLE="${PR_TITLE:-}"
+AUTHOR="${PR_AUTHOR:-}"
+
+# Break-glass: dfritz is exempt from all naming checks.
+if [ "${AUTHOR}" = "dfritz" ]; then
+  echo "check-naming: dfritz break-glass — exempt"
+  exit 0
+fi
+
+WARN=0
+BRANCH_KIND="invalid"
+BRANCH_BUG=""
+
+# ---- branch form ----
+# <role>/bug-<id>/<kebab>
+if echo "${BRANCH}" | grep -qE "^(dev|ux|ops|security|perf|architect|support)/bug-[a-z0-9]+/[a-z0-9][a-z0-9-]*$"; then
+  BRANCH_KIND="role-bug"
+  BRANCH_BUG=$(echo "${BRANCH}" | sed -E 's|^[^/]+/(bug-[a-z0-9]+)/.*|\1|')
+# chore/<kebab>
+elif echo "${BRANCH}" | grep -qE "^chore/[a-z0-9][a-z0-9-]*$"; then
+  BRANCH_KIND="chore"
+else
+  echo "WARN[check-naming]: branch '${BRANCH}' does not match convention"
+  echo "  expected: <role>/bug-<id>/<kebab>  (role: dev|ux|ops|security|perf|architect|support)"
+  echo "         or: chore/<kebab>"
+  WARN=1
+fi
+
+# ---- title form ----
+TITLE_BUG=""
+if echo "${TITLE}" | grep -qE "^\[bug-[a-z0-9]+\] ."; then
+  TITLE_BUG=$(echo "${TITLE}" | sed -E 's|^\[(bug-[a-z0-9]+)\].*|\1|')
+fi
+
+if [ "${BRANCH_KIND}" = "role-bug" ]; then
+  if [ -z "${TITLE_BUG}" ]; then
+    echo "WARN[check-naming]: title missing [${BRANCH_BUG}] prefix for branch '${BRANCH}'"
+    WARN=1
+  elif [ "${TITLE_BUG}" != "${BRANCH_BUG}" ]; then
+    echo "WARN[check-naming]: bug-id mismatch — branch carries '${BRANCH_BUG}' but title carries '${TITLE_BUG}'"
+    WARN=1
+  fi
+elif [ "${BRANCH_KIND}" = "chore" ] && [ -n "${TITLE_BUG}" ]; then
+  echo "WARN[check-naming]: chore branch should not carry a [bug-id] title prefix"
+  WARN=1
+fi
+
+if [ "${WARN}" -eq 0 ]; then
+  echo "check-naming: ok"
+fi
+
+exit 0